Orchard heater



.'Apri1z9,19 1- w. E. NANCE HAL 2,240,224-

ORCHARD HEATER I Filed July 3, 1937 Patented Apr. 29, 194i NT OFFICE- onommn HEATER William E. Nance and James B. Stone, Redlands,

, Calif Application July 3, 1937, Serial No. 151,908

Claims. (Cl. 158-91) This invention relates to outdoor heaters such as are used chiefly for protecting trees from frost and is particularly applicable to oil burning heaters.

An object of the invention is to provide an unusually eflicient and smokeless heater of the type referred to for burning ordinary fuel oil.

A more specific object of the invention is to provide an attachment for installation on heaters of existing types for making such heaters more efiicient, both with respect to'the amount of use-'- ful heat produced and the reduction of smoke.

In co-pending application of William E. Nance, Serial No. 143,099, filed May 17th, 1937 on an Orchard heater, one of the joint inventors here in has disclosed an improvement in oil burning orchard heaters whereby existing heaters of at present widely used types can be improved by substituting for the old cover and stack an im proved cover and stack. In accordance with the present invention, among other things, we provide a collar or coupling which may be inserted between the tank and cover of many existing heaters to improve the operation of the heaters. This collar or coupling is highly advantageous in that it costs less to produce than a complete cover and makes possible the use of the old cover on the old tank. 7

The invention will now be explained by describing in detail with reference to the drawing certain specific embodiments of the invention, it being understood that various changes can be made in the particular structure shown without departing from the invention.

In the drawing: i

Fig. 1 is a side elevational view with a portion broken away of a complete orchard heater of the round tank type equipped in accordance with our invention.

Fig. 2 is a detail vertical sectional view through the lower portion of the heater shown in Fig. 1, the section being taken approximately in the line II-II of Fig. 1.

Fig. 3 is a plan view of the separable collar attachment employed in the heater of Fig. 1.

Fig. 4 is a horizontal section in the plane IV-IV of Fig. 1.

Fig. 5 is a vertical section through the collar shown in Fig. 3, the section being taken in the plane V-V of Fi 3.

Fig. 6 is a Vertical section through a square type orchard heater incorporating our invention;

Fig. 7 is a detail elevational view of the inside of one corner of the tank shown in Fig. 6 with the separable collar positioned above the tank preliminary to attachment to the tank; and

Fig. 8 is a view similar to Fig. 7 but showing the collar inserted in place onthe tank.

Referring first to Fig. 1, the heater therein disclosed comprises as its essential elements a tank I for containing fuel oil, a collar 2 positioned on top of the tank I, and a cover 3 positioned on top of the collar 2, this cover having an outlet flange of reduced size which receive and supports a stack 4.

The tank I is of very simple construction, consisting simply of an open top, flat bottom, cylindricalreceptacle, preferably of seamless or Welded construction so that it will remain liquidtight despite exposure to the weather. These tanks may be constructed in various sizes, usually being approximately 19" in diameter and substantially half as deep, the relative proportions being approximately as shown in the drawmg.

The collar 2' consists of a substantially cylindrical band I of internal diameter at the lower end such as to fit snugly about the upper end of the tank I. It is preferably provided with an inwardly extending circumferential bead 6 positioned slightly above the lower edge, which bead engages the upper edge of the tank I and limits downward movement of the collar on the tank. The band 1 may be 4" 0r 5" in height or width, depending upon the dimensions of the tank-with which it is to be used, and at its upper edge is of slightly smaller diameter than at the lower edge, so that the external diameter of the upper edge approximates the external diameter of the upper edge of the tank I, so that a cover 3 adapted to fit upon the top of the tank I will also fit on top of the band 1. An external circumferentialbead 8 may be provided a short distance below the upper end of the band 1 to limit downward movement of the collar 3 on the band.

The cover 3, as shown in the drawing, is substantially in accordance with prior practice and comprises simply an inwardly and upwardly sloping member having a flange 9 at the upper end defining an outlet opening into the stack 4. It is usually provided with an air inlet opening 10 adapted to be closed by a sliding cover H. In the present invention this opening I0 is not employed and is maintained closed by the cover ll except during ignition of the burner.

Referring now to Figs, 3, 4 and 5, the collar 2 has attached thereto at diametrically opposite points intermediate the lower bead 6 and the upward bead 8 a pair of inwardly and upwardly extending pipes I2 and I3, respectively, which pipes merge into each other and into an air discharge head I4 centrally of the burner immediately below the stack 4. The head I4 is provided with a large number of relatively small air apertures I5, The outer ends of the tubes I2 and I3 communicate with the exterior through apertures provided therefor in the band 1. In operation, air is drawn into the pipes I2 and I3, being heated during its passage therethrough and discharged in numerous small jets through the apertures I5 into the burning gases within the cover 3. This air is intimately mixed with the burning gases, facilitating combustion and increasing the amount of heat produced and reducing the amount of smoke produced;

The tubes I2 and I3 may be of any desired cross-sectional shape but we havefound it convenient to make these tubes of rectangular crosssection and in a tank of average size the tubes may be approximately 1 in vertical cross-sectional dimension and about 3" in horizontal cross-sectional dimension. V

The band! also has attached thereto and downwardly depending therefrom a wall member I6 which, when the collar 2 is assernbied on the tank I, constitutes a false or auxiliary wall slightly spaced inwardly from the main wall of the tank I. The main portion of the wall member I6 may be cylindrically curved so that it fits in concentric relation with the wall of the tank I and extends substantiallyfrom the top of the band 2 to within a fraction of an inch of the bottom of the tank I. It is secured in sealing relation to the band 1 by an outwardly extend: ing flange ll, which flange in turn, at its extreme outer edge, is bent upwardly to constitute a rim I8 which fits against the inner surface of the band I and is secured thereto, as by welding. At its lateral edges, the wall member I6 is also provided with outwardly extending flanges 'I 9 (see Fig. 4) which fit relatively close against the inner surface of the tank I when the collar 2 is positioned thereon. The wall member I6 defines with the juxtaposed portion of the wall of tank I and the band Tan air chamber'extehding from the level of the oil in the tank I up to the flange I1. This air chamber really functions'as an air passage for transmitting air from the exterior into the tank I above the level of the oil therein.

Thus, the wall member I6 is provided with a plurality of vertical slots 20 extending substantially the full length of the member I6 for supplying air through the wall member I6, and the band I is provided with apertures 2| for admitting air from the exterior into the space or chamber defined by the wall'member I6. The amount of air entering the apertures 2I may be controlled by a slide 22 mounted in guides 23 and having apertures 24 therein adapted to be movedinto or out of registration with the apertures 2| by moving the slide circumferentially on the collar. The apertures 2| may be approximately 1" in'diameter and there may be three of them on a heater of average size. The slots 20 may be approximately /8" wide and spaced about l /z'f'apart. The spacing between the wall of the tank and the wall member I6 may be about 1%". The wall member I6 may extend circumferentially about one-third the way around the tank.

It is found that with the structure disclosed, unusually complete combustion is produced, probably by reason of the fact that the air is preheated, to a certain extent, within the recess or chamber defined bythe wall I'S'and'is then discharged in relatively small jets through the slits 20 to mix intimately with the gas burning in the tank. Of course, as the burning gas ascends into the stack 4, it is mixed with additional air discharged through the apertures I5 in the head I4 prior to being discharged into the stack. The apertures I5 may be approximately in diameter and the discharge head I4 may be approximately 3 /2" in diameter and contain in the neighborhood of apertures, all told. This number, of course, may be varied by experiment to determine the optimum number and size for most complete combustion with any particular fuel and a tank of any particular dimensions. I

The stack 4 is preferably constructed in two sections, the lower section comprising a straight tubular member 25 which fits over the flange 9 on the cover 3 and is tapered inwardly slightly at its upper end, like the reduced end of a stove pipe, to fit within and support an upper stack section 26 which is tapered gradually to a reduced diameter at the upper end. The lower stack section 25 is provided with a plurality of flanges 21 extending circumferentially thereabout at spaced intervals and the upper stack section 26 is similarly provided witha plurality of circumferentially spaced'flanges 28. Both flanges 21 and 28 perform the function of radiating heat from the stack sections on which they are mounted, to

surrounding objects. We 'havealso found it desirable to provide in the lower stack section 25 a plurality of air inlet apertures 29, there being a row 'of these apertures 29 below each of the flanges 21. Th'e'draft through the stack is suffici'ent to draw in air through the apertures 29. The upper stack section 26 is also provided with apertures 30, these apertures being positioned belowthe flanges 28. The apertures 30, however, "are preferably substantially larger and fewer in number than the apertures 29 and function as discharge passages for burning gases and prod- 'ucts of combustion, This is byvirtue ofthe fact that the stack 26 is tapered to a reduced diameter at the top. A substantial portion of the burning gases are discharged through the apertures t oagainst'theunder sides of the flanges 28, thereby further heating those flanges and causing them to radiate heat to surrounding objects. In normal operatiomthere will be a small amount of flame issuing from 'each of the apertures 30,

as well as from the upperend of the stack section 26. To facilitate the discharge of flame and burning gases through the discharge apertures 30, an inwardly and downwardly extend- I ing baflie 3| is preferably provided immediately aboveeach of the apertures 30, this construction being fully disclosed and claimed in the copending Nance application previously referred to.

As previously indicated, one of the chief advantages of the present invention is that by the use'of thezband 2,'as described, existing tanks I and covers 3 may be utilized to produce a more eflicient and substantially smokeless heater, it being only necessary for an orchardist owning old type heaters to purchase the bands 2 and the stacks 4 in order to modernize hisequipment.

The equipment so far described relates to burners employing circular or cylindrical. type tanks. However, at present there. are ag'reat many orchard heaters in use which have tanks which are square in horizontal section instead of round. The tanksalso usually have side walls which are flared upwardly and outwardly. Of course, it is obvious that a band' employing air 'iary band and a 'sqiiar 'sults from the fact that air the slots 2!] igardless' of the height of the oil level in the inl t-ampe e as d l1 P q mleetion. with Fi 1 t inlay b made i u relsnanei ada square pots or tanks of existing design. Howth t ts or imc l eyn'we have discovered I tdprovide a t m s between. the auxi e p ank. han en a round top tank. The chief reason for this seems to betha't the flat sides of the square tanks are more apt to" be bent so that it is .diflicultto fit a band to them when the band merely sets on the upper edge. we have also found that it is quite important that the band fit snugly on the tank and preventefiy great amount of air leakage at that point else the operation of the burner is seriously interfered with. We have found that it is feasible, however, to construct a band that will fit snugly on square tanks by employing the construction shown in Figs. 6, 7 and 8. Thus, referring to Fig. 6, the usual square type tank is provided with a rolled or beaded upper edge 5| a, usually formed by wrapping the upper edge of the tank about a rod or wire. The usual cover 53a. for a square tank sets directly on top of the beaded or rolled edge 5Ia. However, as previously indicated, if a tank has been badly bent, it is often impossible to secure a tight connection between a cover or a band and the tank by merely employing a surface on the cover or band adapt ed to set on top of the head Sta. To this end we preferably form a band 32 for a square tank with inwardly and downwardly extending skirt members 33. Thus, the band 32 may be formed of sheet metal bent outwardly and back on itself to form a seat 34 adapted to rest upon the bead 5la. of the tank and then extend the material on down past the seat 34 to form the skirts 33. These skirts 33 extend straight downwardly from the band 32 prior to attachment of the band to the tank. However, the corners of the skirts 33 are cut away, as indicated at 35 in Fig. 7, so that as the band 32 is pressed down onto the tank, the skirts 33 slide along the inner surface of the walls of the straight tank and are bent inwardly, thereby to form a tight fit against the walls of the tank. As a result of this inward bending of the skirt members 33, the corners of the skirts come together substantially as shown in Fig. 8.

Aside from the details mentioned, the construction of the band for a square tank is substantially the same as that for a round tank. Thus, it employs an air inlet head 3! having apertures 38 therein, the head being connected to the exterior and mechanically supported by tubes 39 extending to diametrically opposite points on the band, Likewise, an inner wall member 40 is provided having slots 4| for supplying air to the tank, the flow of the air being controlled through ports 43 in the band by means of a slot 44 having apertures therein. Of course, whereas in the round tank, the false wall extended circumferentially for a portion of the way about the cylindrical wall of the tank, the wall 40 for a square tank would be straight and extend down along only one side of the square tank.

Referring to Fig. 2, it will be observed that oil will be maintained at the same level on both sides of the wall 16 and a certain amount of combustion may take place in the space above the oil between wall l6 and the adjacent wall of the tank. However, because of the small area of the oil surface exposed in this space, most of the air will pass from the apertures 2| through the slots 20 without being consumed and the main vapor generation and combustion takes place beyond the wall l6. Improved operation reis introduced through substantially at. the 011 surface, aretank. It isto be understood'that although the air inlet apertures 20 have been disclosed asvertical slots, they need not necessarily be in this form, and if desired, numeroussmall holes distributed over the wall may .be employed instead of. the vertical slots.

As previously indicated,"the invention'has' been explained by describing in detail certain specific embodiments thereof, it being understood that various changes can be made from the particular structure shown without departing from the invention which is to be defined as set forth in the appended claims.

We claim:

1. An orchard heater of the type described for burning oil, a receptacle for containing oil, said receptacle having an open top, a collar detachably mounted on said receptacle, a cover detachably mounted on said collar and having a discharge aperture therein for a stack, and a stack mounted on and extending upwardly from said cover, said collar incorporatingmeans for supplying air for combustion into the space defined by said receptacle, collar, and cover, the upper edge of said receptacle and the lower edge of said cover being so shaped and dimensioned as to be detachably connectible directly together whereby the heater may be used either with or without said collar.

2. In an orchard heater of the type described for burning oil, a receptacle for containing oil, said receptacle having an open top, a collar detachably mounted on said receptacle, a cover detachably mounted on said collar and having a discharge aperture therein for a. stack, and a stack mounted on and extending upwardly from said cover with a wall member attached to and supported by said collar cooperating with a portion of the wall of said receptacle to define an air inlet passage, said collar having openings therein for admitting air into said inlet passage and said wall member having numerous small openings therein for admitting air from said passage to said receptacle, the upper edge of said receptacle and the lower edge of said cover being so shaped and dimensioned as to be detachably connectible directly together whereby the heater may be used either with or without said collar.

3. A heater as described in claim 2 in which said wall member extends substantially to the bottom of said receptacle and said openings in said wall member are distributed substantially over the full vertical dimension ofsaid .wall member.

4. In a heater of the type described comprising in combination a receptacle for containing oil and generating vapor therefrom and a stack for the combustion of oil vapor generated in said receptacle; the stack construction comprising a first vertical tubular member of substantially uniform dimensions from top to bottom, the lower end of said first section fitting to said receptacle, one or more annular flanges secured to and extending outwardly from said first section, said section having a plurality of air inlet apertures therein immediately below said annular flanges, and a second stack section fitting on top of said first stack section, said second section being tapered from a large diameter at the bottom to a small diameter at the top and being open at the top, a plurality of annular flanges s cu "ing a plurality of air inlet apertures therein immediately below said annular flange, and a second stack section fitting on top of said first stack section, said second section being tapered from a large diameter at the bottom to a small diameter at the top, and being open at the top, a plurality of annular flanges secured to and extending outwardly from said second section, and a plurality of discharge apertures in said second section l0 positioned immediately below the flanges thereon.

WILLIAM E. NANCE. JAMES B. STONE. 

